458 DERIVATIVES OF THE BILE IN THE FJECES. [BOOK II. 



Microscopic On microscopical examination, the faeces of man and 



of animals consuming a mixed diet may exhibit the 

 following structures: vegetable parenchyma, starch 

 granules, spiral vessels, masses of woody fibre, fragments of muscular 

 fibres, fragments of tendon and ligament, yellow elastic fibres, 

 fragments of blood-vessels, masses of fat, crystalline calcium salts of 

 the fatty acids, undissolved nucleins, besides mucus and epithelium 

 which appears to be abundantly exuviated by the intestinal walls. 

 There are also frequently found chlorophylloid matters, crystals of 

 ammoniaco-magnesium phosphate &c. 



The deriva- The brown colour of the normal faeces is due to 



hydrobilirubin. Heynsius and Campbell 1 had ex- 

 matter found pressed the opinion that the colouring matter of the 

 in the excre- faeces was identical with choletelin. Vanlair and 

 ments. Masius a afterwards described the colouring matter of 



Hydrobilirubin. ^Q fgg ces as a body very closely resembling choletelin 

 in properties, especially in spectroscopic characters, but which they 

 considered distinct from it, assigning to it the name of ' Stercobilin.' 

 Jaffe looked upon the colouring matter of the faeces as identical with 

 the urobilin of the urine 3 . Maly 4 , however, subsequently shewed 

 that the colouring matter of the faeces is doubtless the same as 

 the product of reduction which he had obtained from bilirubin and to 

 which he had assigned the name 'hydrobilirubin'. The origin of the 

 latter body from bilirubin, under the influence of the nascent 

 hydrogen, abundantly evolved during intestinal digestive processes, 

 sufficiently explained its occurrence. Notwithstanding the arguments 

 of MacMunn, which are based on minor differences in spectroscopic 

 reactions, the Author is of the opinion, which is shared by nearly 

 all physiological chemists, that the normal colouring matter of the 

 faeces is a product of reduction and is identical with Maly's hydro- 

 bilirubin. 



The deriva- Some undecomposed glykocholic acid has been 



tives of the found, by Hoppe-Seyler, in the excrements of the ox. 

 found in -"- n ^ ne ma i n > however, as has already been repeatedly 



the faeces. insisted on, the greater part of the bile acids are 



removed by absorption, and only small quantities of 

 cholalic and choloidic acids are found in the faeces. It is remarkable 

 that the faeces only contain very small quantities of the extremely 

 resistant taurine. Dressier 5 , by calculating the sulphur existing in 



1 Heynsius and Campbell, op. tit., p. 320. 



2 Vanlair and Masius, 'Neuer Abkommling des Gallenfarbstoffs im Darminhalt,' 

 Centralbl. f. d. med. Wissenschaft, 1871, no. 24. 



3 Max Jaffe, 'Vorkommen von Urobilin im Darminhalt,' Centralblatt f. d. med. 

 Wissenschaft, 1871, no. 30. 



4 Bichard Maly, 'Kiinstliche Umwandlung von Bilirubin in Harnfarbstoff,' Cen- 

 tralblatt f. d. med. Wissensch., 1871, no. 54. 'Umwandlung von Bilirubin in Harnfarb- 

 stoff,' Maly's Jahresber., Vol. n. (1874), p. 233 et seq. See p. 237. 



5 W. Dressier, 'Beitrag zur Kenntniss der excrementiellen Taurin- uud Schwe- 

 felausfuhr beim Menschen,' Prager Vierteljahrsschrift, Vol. LXXXVIII. (1865), p. 1. 



